Zero error code 04
Controller Temperature Warning Stage 1
What it means
Controller Temperature Warning Stage 1
Sevcon controller near upper temperature limit.
Warning — Monitor the situation, may self-resolve.
What to do
- 1Reduce power demand. Allow controller to cool.
Code 04 on the other dash
The number alone is not enough. A Gen2 dash reads code 04 as Controller Temperature Warning Stage 1; a Gen3 dash reads the same number as Throttle Fault. And the model name does not settle it: the S, SR, DS and DSR kept their names when they moved from the Sevcon dash to Cypher III in 2024, so it is the year that tells you which table applies.
Which bikes use this table
Sevcon-era dash: S, SR, DS (2014-2023), DSR (2016-2023), FX (2014-2025), FXS (2016-2021), FXE (2022-2025). The SDS and XMX owner manuals print the same 0-63 table.
Related codes
Other Gen2 Thermal codes:
What the log file records for the same subsystem:
Questions
What does error code 04 mean on a Zero Gen2 dash?
Controller Temperature Warning Stage 1. Sevcon controller near upper temperature limit. It is classed as warning: monitor the situation, may self-resolve.
What should I do about it?
Reduce power demand. Allow controller to cool.
Does code 04 mean the same thing on a Gen3 Zero?
No. On a Gen3 dash, code 4 is "Throttle Fault" — a different fault entirely. The two tables share numbers but not meanings, so read the one that matches your dash, not your model name: the S, SR, DS and DSR kept their names when they moved to Cypher III in 2024.
See when this actually happened on your bike
A dash code tells you the fault; the log tells you the pack temperature, the state of charge and the ten minutes leading up to it.
Sources:
The code and its name are transcribed from Zero's own owner manuals; the severity, category and troubleshooting notes are ours. For official diagnostics, consult an authorized Zero Motorcycles dealer.